Numerical Analysis And Experimental Study Of Anti-ice Vibration Reduction Of Stainless Steel Tubular Concrete Composite Jacket Offshore Platform

With the increasing shortage of terrestrial oil and gas resources,emerging marine industries such as offshore oil and gas development have developed rapidly.As an important infrastructure for the exploitation of marine oil and gas resources,offshore platforms play an important role in the development of marine oil and gas resources.The marine environment and the ice condition of the Bohai are complex and the overlapped and accumulated of sea ice would endangers the safety of the offshore platform.Therefore,in order to ensure the safety and use of offshore platforms,it is necessary to build a new type of offshore platform with ice resistance.Based on the structural form of the JZ20-2 offshore platform in the Bohai Sea area of China,this paper proposes a self-centering stainless steel-concrete-steel tube composite offshore platform.The combination of stainless steel-concrete-steel tube concrete and pre-stress technology is applied to the offshore platform to achieve anti-ice damping and self-centering.The content of this paper mainly includes the following aspects:(1)In order to solve the problem of ice-induced vibration of the offshore platform,the concept of self-centering stainless steel-concrete-steel tube composite jacket offshore platform was proposed.The jacket legs of the original offshore platform were replaced with stainless steel tube concrete structures,and prestressed cables were added to the offshore platform.Four self-centering offshore platforms were designed based on different arrangements of cables.(2)The finite element software ABAQUS is used to establish a full-scale model of the original offshore platform,combined offshore platform and self-centering combined offshore platform,and the ice-induced vibration reduction and self-centering performance studies are carried out.The arrangement of the prestressed cables and the height of cable arrangement are analyzed.This paper provides a new idea for the design optimization of the self-centering combined jacket offshore platform under ice-induced vibration.(3)Taking into account the relevant factors such as feasibility and economy,an offshore platform test model with a scale ratio of 1:10 was designed and manufactured.Ice-induced vibration tests were carried out on the offshore platform models of different systems,and the displacement and acceleration response of the upper deck,lower deck and the end cap anchor plate joints of the platform were analyzed in detail.The vibration reduction effects of different self-centering combined offshore platforms were compared.(4)The experimental model of the offshore platform was modeled by ABAQUS and numerically analyzed under the action of crushing ice load to study its anti-ice damping and self-centering performance.By comparing with the results of the offshore platform test,it is found that the results of the displacement and acceleration of the selected nodes are in good agreement,which verifies the validity of the finite element analysis.